Messages in this thread Patch in this message | | | From | Phong Tran <> | Subject | [PATCH] media: dvb: check return value digitv_ctrl_msg | Date | Tue, 3 Dec 2019 07:41:38 +0700 |
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For fixing syzbot "KMSAN: uninit-value in digitv_rc_query"
In scenario testing for syzbot, failure reading from digitv_ctrl_msg() [1].
Eg: [ 91.846657][ T3844] dvb-usb: bulk message failed: -22 (7/0)
digitv_rc_query() always return 0. But in this case a wrong thing happens.
Reported-by: syzbot+6bf9606ee955b646c0e1@syzkaller.appspotmail.com Tested-by: syzbot+6bf9606ee955b646c0e1@syzkaller.appspotmail.com
[1]: https://syzkaller.appspot.com/text?tag=CrashLog&x=16860a63600000 [2]: https://groups.google.com/d/msg/syzkaller-bugs/-TXIJAZ0J9Q/T4PEUQoeAQAJ
Signed-off-by: Phong Tran <tranmanphong@gmail.com> --- drivers/media/usb/dvb-usb/digitv.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/media/usb/dvb-usb/digitv.c b/drivers/media/usb/dvb-usb/digitv.c index dd5bb230cec1..61bc8945e6b9 100644 --- a/drivers/media/usb/dvb-usb/digitv.c +++ b/drivers/media/usb/dvb-usb/digitv.c @@ -231,17 +231,21 @@ static struct rc_map_table rc_map_digitv_table[] = { static int digitv_rc_query(struct dvb_usb_device *d, u32 *event, int *state) { int i; - u8 key[5]; + u8 key[5] = { 0 }; u8 b[4] = { 0 }; + int ret; *event = 0; *state = REMOTE_NO_KEY_PRESSED; - digitv_ctrl_msg(d,USB_READ_REMOTE,0,NULL,0,&key[1],4); - + ret = digitv_ctrl_msg(d, USB_READ_REMOTE, 0, NULL, 0, &key[1], 4); + if (ret < 0) + return ret; /* Tell the device we've read the remote. Not sure how necessary this is, but the Nebula SDK does it. */ - digitv_ctrl_msg(d,USB_WRITE_REMOTE,0,b,4,NULL,0); + ret = digitv_ctrl_msg(d, USB_WRITE_REMOTE, 0, b, 4, NULL, 0); + if (ret < 0) + return ret; /* if something is inside the buffer, simulate key press */ if (key[1] != 0) -- 2.20.1
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